Method of combating nematodes with aryl isocyanide dihalides



United States Patent 3,164,515 METHOD OF COMBATING NEMATODES WITH ARYL KSGCYANIDE DIHALIDES Bernhard Homeyer, Opladen, Engelbert Kiihie, Cologne- Stammheim, and Hugo Malz, Lever-kusen-Vsiesdorf, Germany, assignors to Farhenfabriiren Bayer Almerigeselisehaft, Leverhusen, Germany, a corporation of Germany No Drawing. Filed May 15, 1962, Ser. No. 194,969 Claims priority, application Germany May 30, 1961 i 7 Claims. (Cl. 16730) The present invention relates to and has as its objects new and useful nematode control agents which contain as active ingredients. isocyanide dihalides of the general formula in which Ar is an optionally substituted aromatic radical and X is chlorine or bromine. These new nematocidal agents possess a good plant tolerance.

Compounds of the abovementioned formula suitable for nematode control are e.g. phenyl-isocyanide dichloride, phenyl-isocyanide dibromide, 4-chlorophenyl-, 2,4- dichlorophenyl-, 4-nitrophenyl-, 4-bromophenyl-, Z-methyl-4-chloroisocyanide dichloride, 4-chloronaphthyl-(1)- isocyanide dichloride and phenylene-(l,4)-bisisocyanide dichloride or the corresponding dibromides.

The inventive compounds are either known or may be prepared to methods known in principle. In the literature the following ways are described to prepare aromatic isocyanide dihalides:

By chlorination of aromatic mustard oils (see E. Sell and G. Zierold: Berichte 7, 1228 (1874);

By addition of halogen to isonitriles (see J. U. Nef Annalen 270, 267 (1892) and Annalen 280, 291 (1894).

Recently a new elegant method has been described which consists in chlorination of formanilides in thionyl chloride, whereby also isocyanide dihalides' may be obtained (see German patent specification 1,094,737).

The compounds to be applied according to the invention can be used as spraying or pouring agent for the surface of the soil infested to be protected, and then Worked in. After a refraining period from cultivation of 3 to 4 Weeks the treated soil can be sown or planted.

If the compounds are used as dust formulations these dust formulations may be prepared by admixing the active ingredient with suitable inert extenders such as talc, chalk, bentonite, fullers earth and the like. Liquid form ulations may be prepared by admixing the active material with any suitable inert diluents; especially suitable are lower aliphatic chlorinated hydrocarbons such as chloroform, halogenated propanes, propenes and the like.

The good nematocidal power of the new compounds according to the invention is apparent from the following experim ents Example The compounds mentioned below were tested against root gall nematodes Meloidogyne incognito. Each time 1 l. of infected soil was treated with 25, 50, 100 and 200 ppm. of these substances. The application of the substances was carried out as a 1% formulation in talc, which was intimately mixed with the soil. A week after the application all the treated samples were sown with lettuce. The latter was evaluated after 4 weeks for gall formation. In the following table the activities in percent are given for each applied amount. Each figure is a mean value from two tests.

Formula 25 50 100 200 p.p.m. p.p.m. ppm. p.p.1n.

Percent Percent Percent Percent 01 N=G on 100 100 100 100 01 ClN=CCh so ion c1 N=C C11 0 50 100 100 c1 N=oon 95 100 100 100 N=C on 50 100 100 100 BrQ-Nfl] on 05 100 100 100 Br I Br- -N=001i 50 98 100 100 o1 -N=C on 0 so 100 100 oon=n-1s=oon o o 50 9s 01 01-N=0 on 90 100 100 100 We claim:

1. Method of combating nematodes which comprises applying to soil an isocyanide-dihalide of the formula the formula 01-( N=CC12 3. A method of combating nematodes which comprises applying to soil an active amount of a compound having the formula 4. A method of combating nematodes which comprises applying to soil an active amount of a compound having the formula 5. A method of combating nematodes which comprises applying to soil an active amount of a compound having the formula 13 r-N=C 012 6. A method of combating nematodes which comprises applying to soil an active amount of a compound having the formula References Cited in the file of this patent FOREIGN PATENTS 1,094,937 Germany Dec. 15, 1960 OTHER REFERENCES I Chem. Abst., vol 53, page 18017; vol. 36, page 3491; vol. 35, page 442; vol. 34, pages 2806, 2807, 3492. Pat

ent Ofiice Scientific Library.

Berichte 7, 1228 (1874).

20 Annalen 270, 267 (1892); 280, 291 (1894). 

1. METHOD OF COMBATING NEMATODES WHICH COMPRISES APPLYING TO SOIL AN ISOCYANIDE-DIHALIDE OF THE FORMULA 